1. Field
This application relates to systems for physical vapor deposition processing, such as sputtering systems used in the fabrication of solar cells, flat panel displays, touch screens, etc.
2. Related Art
Various systems are known in the art for fabricating semiconductor IC's, solar cells, touch screens, etc. The processes of these systems are conducted in vacuum and include, e.g., physical vapor deposition (PVD—also referred to as sputtering), chemical vapor deposition (CVD), ion implant, etch, etc. There are two basic approaches for such systems: single-substrate processing or batch processing. In single wafer processing, only a single substrate is present inside the chamber during processing. In batch processing several substrates are present inside the chamber during processing. In the fabrication of flat panel displays and other large substrates, even a single substrate may require a correspondingly large source, e.g., sputtering source and target. Similarly, a large source and target is needed when processing a batch of several smaller substrates simultaneously.
Large sputtering sources are complex and expensive to manufacture. They require complex design of magnetron, cooling system, etc. Also, due to their sheer size they are difficult to maintain. Moreover, the target becomes very expensive to manufacture and leads to underutilization due to the difficulties in uniformly sputtering from the entire surface of a large target. This increases the cost of ownership of such systems.